fix: use correct types for plex item typehints

[ReenigneArcher]

Description

Fix typehints for plex items.

Screenshot

Issues Fixed or Closed

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Dependency update (updates to dependencies)
• Documentation update (changes to documentation)
• Repository update (changes to repository files, e.g. .github/...)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the in code docstring/documentation-blocks for new or existing methods/components

Branch Updates

LizardByte requires that branches be up-to-date before merging. This means that after any PR is merged, this branch
must be updated before it can be merged. You must also
Allow edits from maintainers.

• I want maintainers to keep my branch updated

[codecov]

Codecov Report

Merging #211 (06ed1fe) into nightly (b463749) will increase coverage by 3.20%.
The diff coverage is 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##           nightly     #211      +/-   ##
===========================================
+ Coverage    63.94%   67.14%   +3.20%     
===========================================
  Files           10       10              
  Lines          760      761       +1     
===========================================
+ Hits           486      511      +25     
+ Misses         274      250      -24     

Flag	Coverage Δ
Linux	63.99% <100.00%> (+0.04%)	⬆️
Windows	67.14% <100.00%> (+39.51%)	⬆️
macOS	67.14% <100.00%> (+39.51%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
Contents/Code/plex_api_helper.py	48.17% <100.00%> (+7.51%)	⬆️

... and 1 file with indirect coverage changes